Primary pulmonary plasmacytoma accompanied by overlap syndrome: A case report and review of the literature

BACKGROUND: Extramedullary plasmacytoma (EMP) is a rare kind of soft tissue plasma cell neoplasm without bone marrow involvement; this type of plasma cell neoplasm involves a lack of other systemic characteristics of multiple myeloma. Primary pulmonary plasmacytoma (PPP), with no specific clinical manifestations, is an exceedingly rare type of EMP. Because of its complexity, PPP is often difficult to diagnose, and there is no report in the literature on cases accompanied by overlap syndrome (OS). CASE SUMMARY: A 61-year-old woman without a familial lung cancer history was admitted to our hospital in 2018, for intermittent cough, expectoration, and a stuffy feeling in the chest for 50 years; these symptoms appeared intermittently, especially occurred after being cold, and had been aggravated for the last 10 d. She was diagnosed with pulmonary fibrosis and emphysema, bronchiectasis, OS, and autoimmune hepatic cirrhosis in 2017. A pulmonary examination revealed rough breath sounds in both lungs; other physical examinations found no obvious abnormalities. A routine laboratory work-up showed decreased haemoglobin, increased ESR, and abnormal GGT, ALT, IgG, γ-globulin, κ-light chain, λ-light chain, rheumatoid factor, and autoimmune antibodies. Emission computed tomography demonstrated abnormally concentrated (99m)Tc-MDP. Chest computed tomography revealed a soft tissue mass in the middle and lower lobes of the right lung. After right middle and inferior lobe resection with complete mediastinal lymph node dissection, immunohistochemical analysis revealed an isolated pulmonary plasmacytoma. The patient received chemotherapy for more than 1.5 years and remains in good general condition. CONCLUSION: PPP is a type of EMP, and we report an exceedingly rare presentation of PPP accompanied by OS.